How to bleed & replace brake fluid on a 2020 Suzuki King Quad 400ASi 4X4 AUTO

Shop parts for a 2020 Suzuki King Quad 400ASi 4X4 AUTO ATV.

This MotoSport guide gives step-by-step, model-specific instructions to properly flush and bleed the brake system on the 2020 Suzuki King Quad 400ASi 4X4 AUTO, plus what to inspect and note for this MMY ATV.

Safety & preparation

  • Work on level ground with the engine off, key removed, parking brake on, and wheels chocked.
  • Wear gloves and eye protection. Brake fluid is corrosive to paint & plastics.
  • Use the brake fluid type specified in your owner’s manual (commonly DOT 3 or DOT 4). Do not mix different DOT types.
  • Have these tools: clear plastic tubing, a clean catch bottle, wrench for bleed nipples (usually 8mm or 10mm), turkeybaster or syringe, funnel, brake fluid, clean rags, jack and stands or ramps, and optionally a vacuum or pressure bleeder.
  • Protect painted surfaces: cover the tank, frame, and bodywork around the master cylinder and calipers with cloths.

Model notes for the 2020 King Quad 400ASi

  • The King Quad 400ASi uses a hydraulic brake system with a single master reservoir that supplies both front and rear circuits. Keep the reservoir level monitored at all times during bleeding.
  • Braking components are compact on ATVs — take care removing wheels or working near shocks and CV boots. Inspect caliper bolts, flexible hoses, banjo bolts, and sealing washers for leaks or damage while you work.
  • If your unit is equipped with a combined braking system or linked function, maintain the recommended bleed sequence to avoid trapped air. If uncertain, follow the farthest-to-nearest wheel method below.
  • Some King Quad models have ABS or sensor wiring; avoid using high-pressure flushing that could damage sensors. If ABS is present, consult the manual for any ABS-specific bleeding steps before proceeding.

Overview of the procedure

Goal: replace old fluid with fresh fluid and remove all air. Work one wheel/caliper at a time, keep the reservoir full, and follow a logical wheel sequence.

Step-by-step bleed & fluid replacement

  1. Locate the master cylinder reservoir (usually under a small cover near the handlebars). Clean the cap area thoroughly to prevent contamination, then remove the cap and diaphragm.
  2. Siphon out most of the old fluid from the reservoir using a turkeybaster or syringe. Dispose of old fluid properly.
  3. Top the reservoir with fresh brake fluid to the recommended level. Keep the cap loose but in place if using a pressure bleeder; if not, leave it off but continually monitor level.
  4. Raise the ATV so wheels involved are off the ground and accessible. Secure with stands.
  5. Identify bleed nipples at each caliper. Wipe clean and fit a short length of clear tubing over the nipple, with the other end submerged in a small catch bottle containing a little fresh fluid to avoid drawing air back in.
  6. Determine bleed order: use farthest-from-master-first. Typical sequence for this ATV is rear-right, rear-left, front-right, front-left. If your reservoir location or brake plumbing differs, use the farthest-first approach or confirm in your manual.
  7. Open the first caliper bleed nipple about one half turn. Have an assistant slowly depress the brake pedal (or lever) several times and hold it down. With the pedal depressed, open the nipple slightly to let fluid & air escape into the tubing, then close the nipple before the assistant releases the pedal. Repeat until clear, bubblefree fluid appears and pedal feel is firm. If using a vacuum/pressure bleeder, follow that tool’s instructions but keep reservoir topped up.
  8. Keep topping the master reservoir between bleeds. Never let it run low while any bleed line is open.
  9. Repeat the process at each caliper following the sequence. After finishing the last caliper, perform one final bleed pass on each caliper in reverse sequence or as needed to ensure consistent pedal/lever firmness.
  10. When satisfied, tighten all bleed nipples to proper snugness (do not over-torque). Wipe clean any spilled fluid and replace/dry the reservoir diaphragm and cap, ensuring a proper seal.
  11. Lower the machine, torque wheels and caliper bolts to specification, and test brakes at low speed in a safe area to confirm proper operation before regular riding.

Tips & troubleshooting

  • If the brake lever or pedal stays spongy after several attempts, consider bench bleeding the master cylinder or repeating the whole sequence — trapped air in the master cylinder is common.
  • Use new copper crush washers for banjo bolts if you remove lines. Inspect hoses for cracks or soft spots — replace if any deterioration is found.
  • If fluid is dark or contaminated, flush until fluid runs clear and light in color. Multiple reservoir refills and bleeds may be required.
  • Do not top off with different DOT fluids; always fully replace with the same type specified for the bike.
  • If your 400ASi has ABS and you can’t restore firm pedal feel, get the system diagnosed by a dealer or qualified shop familiar with Suzuki ABS implementations.

Final inspection & maintenance

  • After a few short test rides, recheck fluid level and inspect for leaks around calipers, hoses, banjo bolts, and master cylinder.
  • Record the service date and mileage. Brake fluid absorbs moisture over time — schedule replacements at the interval recommended in the Suzuki maintenance schedule.

Follow these steps to ensure safe, reliable braking on your 2020 Suzuki King Quad 400ASi 4X4 AUTO. If you encounter persistent issues or ABS complications, contact a qualified Suzuki technician.

Related Shopping Categories

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Shop Brake Tools for a 2020 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.